We develop a GMPLS control plane handling flex-grid enabled Elastic Optical Networks. The implementation is realized in OPNET Modeler event driven simulation tool with focus on developing and implementing extensions for the GMPLS protocol suite. RSVP-TE extensions address the reservation of generalized labels format and enable enhancements for the wavelength selection procedures. OSPF-TE enables the creation of spectrum databases based on novel LSA sub-TLV attributes capable of advertising spectrum status. Based on the implemented extensions, we propose and evaluate advanced distributed spectrum allocation schemes and strategies for dynamic routing algorithms in support of flex-grid optical networks.